Radio frequency (RF) components, assembled boards and modules radiate both desirable and undesirable emissions. The desirable emissions are those that the components, assembled boards and modules are designed to emit. The undesirable emissions should be suppressed to avoid interference with other equipment. In cellular base station equipment, this is especially true because of the close proximity of other components, assembled boards and modules in the base station. Such components may also be subjected to undesirable RF emissions from external sources.
Attempts have been made to provide shielding and grounding to suppress unwanted emissions between RF modules that are mounted closely together and plugged into a common backplane. One attempt to solve this problem utilizes a conductive adhesive gasket and a conductive adhesive tape. The conductive adhesive gasket is applied to the RF module chassis and the conductive adhesive tape is applied to the backplane. When the RF module is mounted, the gasket on the RF module chassis touches the tape on the backplane.
Unfortunately, the adhesive backed gasket is fragile and tends to become damaged with repeated removal and handling of the RF module. The adhesive backed gasket may also peel off rather easily if the backplane surface has not been cleaned and prepared properly prior to application of the gasket. The damaged gasket may fail to seal properly, or worse, may physically interfere with the mounting of the module. Another shortcoming of this technique is that the gasket and the tape are typically aligned and applied by hand. The conductive tape should be properly located to allow proper electrical contact with other portions of the backplane and the mounting frame to which it is fastened. The mounting surfaces should be prepared properly by cleaning, which is also typically a hand operation. The results are often inconsistent, leading to poor quality and poor shield performance.